Thyroid Doses to French Polynesians Resulting from Atmospheric Nuclear Weapons Tests: Estimates Based on Radiation Measurements and Population Lifestyle Data.

Thyroid doses were estimated for the subjects of a population-based case-control study of thyroid cancer in a population exposed to fallout after atmospheric nuclear weapons tests conducted in French Polynesia between 1966 and 1974. Thyroid doses due to (1) intake of I and of short-lived radioiodine isotopes (I, I, I) and Te, (2) external irradiation from gamma-emitting radionuclides deposited on the ground, and (3) ingestion of long-lived Cs with foodstuffs were reconstructed for each study subject. The dosimetry model that had been used in 2008 in Phase I of the study was substantially improved with (1) results of radiation monitoring of the environment and foodstuffs, which became available in 2013 for public access, and (2) historical data on population lifestyle related to the period of the tests, which were collected in 2016-2017 using focus-group discussions and key informant interviews. The mean thyroid dose among the study subjects was found to be around 5 mGy while the highest dose was estimated to be around 36 mGy. Doses from I intake ranged up to 27 mGy, while those from intake of short-lived iodine isotopes (I, I, I) and Te ranged up to 14 mGy. Thyroid doses from external exposure ranged up to 6 mGy, and those from internal exposure due to Cs ingestion did not exceed 1 mGy. Intake of I was found to be the main pathway for thyroid exposure accounting for 72% of the total dose. Results of this study are being used to evaluate the risk of thyroid cancer among the subjects of the epidemiologic study of thyroid cancer among French Polynesians.

Measurement of the 100 MHz EMF radiation in vivo effects on zebrafish D. rerio embryonic development: A multidisciplinary study.

The augmented exposure of both environment and human being to electromagnetic waves and the concomitant lack of an unequivocal knowledge about biological consequences of these radiations, raised public interest on electromagnetic pollution. In this context, the present study aims to evaluate the biological effects on zebrafish (ZF) embryos of 100 MHz radiofrequency electromagnetic field (RF-EMF) exposure through a multidisciplinary protocol. Because of the shared synteny between human and ZF genomes that validated its use in biomedical research, toxicology and developmental biology studies, ZF was here selected as experimental model and a measurement protocol and biological analyses have been set up to clearly discriminate between RF-EMF biological and thermal effects. The results showed that a 100 MHz EMF was able to affect ZF embryonic development, from 24 to 72 h post fertilization (hpf) in all the analyzed pathways. Particularly, at the 48 hpf stage, a reduced growth, an increased transcription of oxidative stress genes, the onset of apoptotic/autophagic processes and a modification in cholesterol metabolism were detected. ZF embryos faced stress induced by EMF radiation by triggering detoxification mechanisms and at 72 hpf they partially recovered from stress reaching the hatching time in a comparable way respect to the control group. Data here obtained showed unequivocally the in vivo effects of RF-EMF on an animal model, excluding thermal outcomes and thus represents the starting point for more comprehensive studies on dose response effects of electromagnetic fields radiations consequences.

Micronuclei formation in rainbow trout cells exposed to multiple stressors: Morpholine, heat shock, and ionizing radiation.

Discharges from industrial cooling water systems can include low levels of morpholine (a chemical pH regulator and corrosion inhibitor), as well as transiently higher temperature effluent water which present a potential source of environmental impact to aquatic biota. The effects of environmental levels of morpholine or heat shock (HS) treatment alone and in combination with a challenge high-dose of 137Cs ionizing radiation were studied using the cytokinesis block micronucleus assay in a rainbow trout cell line (RTG-2). Morpholine treatment of 10 or 100mgL-1 alone produced no significant effects, and no interaction was observed in combination with 7.75Gy radiation. A 9°C magnitude HS treatment alone significantly increased micronuclei formation. A synergistic response was observed when 9°C HS was combined with 7.75Gy radiation, with 15% more cells containing 3 or more micronuclei than the sum of each individual stressor. A synergistic increase in the average number of micronuclei was observed when morpholine and a 9°C HS were co-treated. These results indicate that morpholine at environmentally-relevant levels does not impact micronuclei formation or cell cycle progression however 9°C HS may be of potential concern both alone and in combination with other stressor treatments.

[Ecological-hygienic evaluation of the environment of territories being adjacent to decultivated uranium mines].

On the territory of Kazakhstan there are uranium deposits, many ofwhich are in mothballed since times of perestroika. Often, the mines are flooded and represent a "time-delay bomb". Inside of mines various there are accumulated gases of both organic and inorganic nature, periodically thrown out and adversely affecting on the health of local populations. The aim of the study was the investigation of the state of the environment of Esilsky district of the Akmola region by common pollutants and chemicals. As the basic variable for the investigation of ambient air there was accepted the maximum one-time concentration of suspended substances, phenol, nitrogen dioxide, sulfur dioxide. The results were evaluated in relation to the MPC for the analyzed substance in the air according to maximal single MPC (MPCms) and daily average MPC (MPCda). The content of metals in the water was determined with the use of spectrophotometer PD-303S. Evaluation of the results was executed in relation of the MPC of substances in water, by means of the comparison with the requirements of Federal standards for drinking water, samples from drinking water sources. There were executed calculations of the overall index of water pollution (IWVgen), the index of water pollution by heavy metals (IWVhm). Chemical analysis of soil was carried out with the use of spectrophotometer PD- 303S (Japan), the photometer expert-003 "Ekoniks". Evaluation of the results was carried out with the respect to the MPC in the soil, the toxicity of all components. Summarizing soil pollution index was evaluated for metals contained in the soil at the level of more than or equal to 1 MAC. The settlement Krasnogorskiy and the village of Kalachi were found to be characterized by a low level of air pollution, increased rigidity of drinking water exceeded the maximum permissible concentrations of copper by 3.45 times and chloride by 1.17 times in the soil cover.

[Current Activity Levels of Artificial Radionuclides in Water Facilities Located at the Semipalatinsk Test Site].

The current data of radioecological research within the Semipalatinsk test site (STS) are presented in the pa- per. It has been shown that almost 90% of polygon lands can be returned to the national economy. Waters of water facilities located at conditionally "background" territories of the STS do not present a radiation hazard to population. Waters of the potential water facilities located close to the radiation hazardous facilities have an increased level of the specific activity of individual radionuclides. Recommendations for the radiological assessment of the quality of waters in water facilities located near radiation hazardous facilities and adjacent territories of STS are offered in the article.

External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio.

In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

Release, deposition and elimination of radiocesium ((137)Cs) in the terrestrial environment.

Radionuclide contamination in terrestrial ecosystems has reached a dangerous level. The major artificial radionuclide present in the environment is (137)Cs, which is released as a result of weapon production related to atomic projects, accidental explosions of nuclear power plants and other sources, such as reactors, evaporation ponds, liquid storage tanks, and burial grounds. The release of potentially hazardous radionuclides (radiocesium) in recent years has provided the opportunity to conduct multidisciplinary studies on their fate and transport. Radiocesium's high fission yield and ease of detection made it a prime candidate for early radio-ecological investigations. The facility setting provides a diverse background for the improved understanding of various factors that contribute toward the fate and transfer of radionuclides in the terrestrial ecosystem. In this review, we summarize the significant environmental radiocesium transfer factors to determine the damaging effects of radiocesium on terrestrial ecosystem. It has been found that (137)Cs can trace the transport of other radionuclides that have a high affinity for binding to soil particles (silts and clays). Possible remedial methods are also discussed for contaminated terrestrial systems. This review will serve as a guideline for future studies of the fate and transport of (137)Cs in terrestrial environments in the wake of the Fukushima Nuclear Power Plant disaster in 2011.

Modeling analysis of the lymphocytopoiesis dynamics in chronically irradiated residents of Techa riverside villages.

A biologically motivated dynamical model of the lymphocytopoietic system in irradiated humans is applied here to analyze the data obtained under hematological examinations of residents of Techa riverside villages. Those people were exposed to chronic irradiation with varying dose rates, due to the radioactive contamination of the river basin by the Mayak Production Association. Modeling studies revealed the relationship between the dynamics of the lymphocytopoietic system in the examined individuals and the variation of dose rate over the considered period of time. It is found that the developed model is capable of reproducing the decreased level of blood lymphocyte concentration observed during the period of maximum radiation exposure, the recovery processes in the system observed during the period of decreasing dose rate, as well as the enhanced mitotic activity of bone marrow precursor cells in this hematopoietic lineage observed during the entire period under consideration. Mechanisms of these effects of chronic irradiation on the human lymphocytopoietic system are elucidated based on the applied model. The results obtained demonstrate the efficiency of the developed model in the analysis, investigation, and prediction of effects of chronic irradiation with varying dose rate on the human lymphocytopoietic system. In particular, the developed model can be used for predicting any radiation injury of this vital system in people exposed to chronic irradiation due to environmental radiological events, such as anthropogenic radiation accidents or radiological terroristic attacks.

Analysis of hematopoiesis dynamics in residents of Techa riverside villages chronically exposed to nonuniform radiation: modeling approach.

A profound approach to the analysis of clinical data on the dynamics of major hematopoietic lineages (granulocytopoietic, thrombocytopoietic, and erythrocytopoietic systems) in chronically irradiated humans is proposed. It is based on recently developed mathematical models of these systems in humans, which enable one to study and interpret clinical hematological data. The developed approach is applied to the analysis of statistically processed clinical data, which were obtained under hematological examinations of residents of Techa riverside villages. These people were exposed to chronic irradiation with varying dose rate due to the radioactive contamination of the river basin by the Mayak Production Association. In the course of modeling studies, the relationship between the dynamics of aforementioned systems in examined individuals and the variation of chronic exposure dose rate over the considered period of time is revealed. It is found that the models are capable of reproducing common regularities and peculiarities of the dynamics of systems on hand, including the decreased stationary levels of blood cell concentrations during the period of maximum radiation exposure, the recovery processes during the period of decrease of exposure dose rate, and the prevalence of younger bone marrow granulocytopoietic cells over more mature ones during the entire period. The mechanisms of such effects of chronic irradiation on the hematopoietic lineages are revealed on the basis of modeling studies. All this testifies to the efficiency of employment of the developed models in the analysis, investigation, and prediction of effects of chronic irradiation on human hematopoietic system.

[Assessment of cyto- and genotoxicity of natural waters in the vicinity of radioactive waste storage facility using Allium-test].

Efficacy of bioassays of "aberrant cells frequency" and "proliferative activity" in root meristem of Allium cepa L. is studied in the present work for a cyto- and genotoxicity assessment of natural waters contaminated with 90Sr and heavy metals in the vicinity of the radioactive waste storage facility in Obninsk, Kaluga region. The Allium-test is shown to be applicable for the diagnostics of environmental media at their combined pollution with chemical and radioactive substances. The analysis of aberration spectrum shows an important role of chemical toxicants in the mutagenic potential of waters collected in the vicinity of the radioactive waste storage facility. Biological effects are not always possible to explain from the knowledge on water contamination levels, which shows limitations of physical-chemical monitoring in providing the adequate risk assessment for human and biota from multicomponent environmental impacts.

Prolong Restoration of the Water Quality of River Ganga Effect of Heavy Metals and Radioactive Elements.

The genesis of the present research was the belief since ages and the observations made through some studies that the water of river Ganga has unique characteristics, which allows storage of water quality even on prolong storage. Very few systematic studies have been conducted to support the contention that the Ganga water indeed has some special composition that could be attributed to its unique storage capacity. It was postulated that prolong restoration of water quality depends on the ability to arrest microbial activity that is generally responsible for deterioration in water quality on prolong storage. Hence, attempt has been made to identify the parameters that are likely to influence the prolong storage of river water. Along with Ganga river water, other three major rivers, viz. Yamuna, Godavari and Narmada, were selected for comparison. Emphasis was made on estimation of heavy metals, radioactive elements, dissolved carbon and other physicochemical parameters such as temperature, pH, alkalinity, hardness and dissolved organic carbon. Based on the available information regarding the impact of heavy metals, radioactive elements vis-à-vis the chemical composition of water on microorganisms in the aquatic environment, an overall impact score for the waters of the four Indian rivers selected in the study has been assigned.

A new approach to predicting environmental transfer of radionuclides to wildlife: a demonstration for freshwater fish and caesium.

The application of the concentration ratio (CR) to predict radionuclide activity concentrations in wildlife from those in soil or water has become the widely accepted approach for environmental assessments. Recently both the ICRP and IAEA have produced compilations of CR values for application in environmental assessment. However, the CR approach has many limitations, most notably, that the transfer of most radionuclides is largely determined by site-specific factors (e.g. water or soil chemistry). Furthermore, there are few, if any, CR values for many radionuclide-organism combinations. In this paper, we propose an alternative approach and, as an example, demonstrate and test this for caesium and freshwater fish. Using a Residual Maximum Likelihood (REML) mixed-model regression we analysed a dataset comprising 597 entries for 53 freshwater fish species from 67 sites. The REML analysis generated a mean value for each species on a common scale after REML adjustment taking account of the effect of the inter-site variation. Using an independent dataset, we subsequently test the hypothesis that the REML model outputs can be used to predict radionuclide, in this case radiocaesium, activity concentrations in unknown species from the results of a species which has been sampled at a specific site. The outputs of the REML analysis accurately predicted (137)Cs activity concentrations in different species of fish from 27 Finnish lakes; these data had not been used in our initial analyses. We recommend that this alternative approach be further investigated for other radionuclides and ecosystems.

Radioactivity in drinking water: regulations, monitoring results and radiation protection issues.

INTRODUCTION: Drinking waters usually contain several natural radionuclides: tritium, radon, radium, uranium isotopes, etc. Their concentrations vary widely since they depend on the nature of the aquifer, namely, the prevailing lithology and whether there is air in it or not. AIMS: In this work a broad overview of the radioactivity in drinking water is presented: national and international regulations, for limiting the presence of radioactivity in waters intended for human consumption; results of extensive campaigns for monitoring radioactivity in drinking waters, including mineral bottled waters, carried out throughout the world in recent years; a draft of guidelines for the planning of campaigns to measure radioactivity in drinking water proposed by the Environmental Protection Agency (ARPA) of Lombardia.

Fatty acid composition of muscle tissue measured in amphibians living in radiologically contaminated and non-contaminated environments.

Fatty acid composition was identified as a potential biological indicator of the effects of environmental exposure to radiological contaminants. This end point was measured in muscle tissues of Mink frogs ( Rana septentrionalis ) obtained from a radiologically contaminated pond and from a non-contaminated pond. It was also measured after the frogs obtained from both ponds were exposed to a 4 Gy (60)Co γ radiation dose delivered in vivo at a dose rate of approximately 8 Gy/min. Statistically significant differences for the increase of a couple of polyunsaturated omega-3 fatty acid residues and the decrease of a polyunsaturated omega-6 fatty acid residue were observed between radiologically contaminated and non-contaminated frogs, indicating a partial remodeling of muscle lipids in response to a chronic low-dose tritium exposure. The effects of an acute high-dose exposure to (60)Co γ radiation, either for the radiologically contaminated or non-contaminated frogs indicated fast post-irradiation fatty acid changes with an increase of polyunsaturated and decrease of saturated fatty acid contents. Fatty acid composition was found to be a sensitive marker that may be useful to study and monitor biota health in environments that are radiologically contaminated, as well as for understanding the differences between low chronic and high acute stress responses.

[Status of hemapoiesis in residents of the Techa riverside villages in the period of maximum radiation exposure. Report 1. Evaluation of the cellular composition of peripheral blood and the role of comorbidities in the oppression of hemapoiesis].

Residents of the Techa riverside villages chronically exposed to ionizing radiation (the average dose rate in 1951-1956 was 0.047 Gy/year, the maximum reached 2.44 Gy/year) developed marked changes in the cellular composition of peripheral blood. The maximum reduction of peripheral blood counts occurred in the years 1951-1953, after which the beginning of the restoration of cellularity to the control level was observed. The dose rate at this point (1956) was about 0.02 Gy/year. The factors of radiation and non-radiation nature (gender, the age at the onset of exposure, health related disorders) in different combinations affect the number of peripheral blood cells. The influence of dose rate of a chronic radiation exposure on a platelet count takes precedence over other factors. The factors of gender and dose rate determine the number of erythrocytes in exposed persons. The changes accompanying the health status and dose rate significantly affect the number of neutrophils. The influence of comorbidity, age and dose rate on the number of monocytes was noted. A lymphocyte count was mainly determined by the age at the onset of exposure and concomitant diseases. A joint influence of chronic radiation exposure and concomitant diseases increases a mutual action on erythro- and thrombocytopoiesis. The decrease of the dose rate was followed by a gradual predominance of the somatic disease influence on leukocyte (neutrophils, lymphocytes and monocytes) counts.

[Status of hemapoiesis in residents of the Techa riverside villages in the period of maximum radiation exposure. Report 2. Influence of exposure dose and dose rate of red bone marrow as well as modifying factors on the frequency of cytopenia and cytosis].

The purpose of this study is a retrospective estimation of the influence of dose and dose rate of the red bone marrow chronic radiation exposure in combination with various modifying factors (gender, age, comorbidity) on the frequency of deviations from normal values of the results of peripheral blood investigation in humans exposed on the Techa River. The results of investigation show that humans chronically exposed to radiation can develop marked changes in the cellular composition of peripheral blood characterized by a tendency to cytopenia (signs of the decompensation of hemopoiesis). The tendency to cytopenia can be identified earlier in the lymphoid germ, and later in platelet and erythroid lines. A high lability of granulocytes under the influence of various, often infectious, factors is the cause of the lack of statistically significant differences in terms of frequency of neutropenia. Several non-radiation factors (gender, age, health status) in combination with radiation exposure could have a modifying influence on hematopoiesis, which contributed to the disruption of adaptation processes and the development of conditions characterized by a tendency to cytopenias in exposed individuals. The red bone marrow dose rate reduction resulted in a gradual decrease in the frequency of erythrocytopenia, thrombocytopenia, neutropenia and lymphocytopenia in the group of exposed population. Increased frequencies of erythrocytosis, thrombocytosis, lymphocytosis, monocytosis and neutrophilia were observed when the median dose rate was reduced to the level of 0.024 Gy/year (in the year 1956), which could be regarded as activation of regenerative processes in hematopoiesis.

[Adaptive response of blood lymphocytes as a marker of hemopoiesis status in exposed persons].

An obvious correlation between the type of reaction manifested by peripheral blood lymphocytes to low dose irradiation in vitro (adaptive potential), the RBM cell composition (during the period of the major exposure), and the peripheral blood cell composition (at a late time period coincident with the studies of induced radioresistance) has been found in the Techa riverside residents in the later periods after the onset of a long-term low-dose rate radiation exposure (55-60 years later) within a range of individual red bone marrow doses from 0.01 to 1.79 Gy. The nature of these dependences observed in chronically exposed individuals differs from that revealed in the controls. It can be suggested based on the results of the study that the capacity for the adaptive response shown by peripheral blood lymphocytes donated by exposed persons in the remote period after exposure can be regarded as a biological marker of the functional state of the hemopoietic stem cell pool.

Groundwater uranium and cancer incidence in South Carolina.

OBJECTIVE: This ecologic study tested the hypothesis that census tracts with elevated groundwater uranium and more frequent groundwater use have increased cancer incidence. METHODS: Data sources included: incident total, leukemia, prostate, breast, colorectal, lung, kidney, and bladder cancers (1996-2005, SC Central Cancer Registry); demographic and groundwater use (1990 US Census); and groundwater uranium concentrations (n = 4,600, from existing federal and state databases). Kriging was used to predict average uranium concentrations within tracts. The relationship between uranium and standardized cancer incidence ratios was modeled among tracts with substantial groundwater use via linear or semiparametric regression, with and without stratification by the proportion of African Americans in each area. RESULTS: A total of 134,685 cancer cases were evaluated. Tracts with ≥50% groundwater use and uranium concentrations in the upper quartile had increased risks for colorectal, breast, kidney, prostate, and total cancer compared to referent tracts. Some of these relationships were more likely to be observed among tracts populated primarily by African Americans. CONCLUSION: SC regions with elevated groundwater uranium and more groundwater use may have an increased incidence of certain cancers, although additional research is needed since the design precluded adjustment for race or other predictive factors at the individual level.